Material handling apparatus



p 5, 1932- SCHROEDER 1.8523

MATERIAL HANDLING APPARATUS Filed Jan. 11, 1950 //7 Vzf/Y for QRMW ofsix such spaced apertures are shown. Extending the entire length of thearms 2020 is a pair of stiffening flanges 47-47.

The hooks 39, 39 consist of a body portion 50 having an upper rightangular extension 51, the hook being provided with upper and lower lips53-53 and a recess 54. The body portion 50 of the hook carries a clevis55 which is rotatable about a pin 57 horizontally extending through thebody portions.

To illustrate the operation of the device it may be supposed that it isdesired to hoist the trailer from the floor level of a warehouse to anelevated gallery for storage. The hoisting crane which carries thetackle 19 is swung over the loaded trailer and, the tackle is suspendedimmediately above the pile of lumber 17. While in such position theparallel arms 19 are balanced to assume a substantially horizontalposition, such as will facilitate their placement relative to the load,by moving the counter-weight 43 from one to the other of the spacingapertures 46, 46, moving it centerward with reference to the length ofthe arms 19 if the weight of the chains 38 and hooks 39 is insulficientto overcome the weight of "the counter-weigit 43, or moving it to theextreme end of the arms 19, if it is found that the weight of thesuspended chains and hooks tends-to raise the counter-weighted end ofthe arms 19 above a substantially horizontal position. It is importantto have the arms 19 substantially horizonal or in other words parallelwih the upper surface of the lumber pile 17 in order toinsure, when thetackle has been lowered thereupon and slack produced in the hoistingchain of the crane. that it be found to lie true with the pile of lumbercomprising the load. This is especially desirable to save labor andtime, where, as is usually the case, the weight of the load issufficiently great and service conditions are sufliciently severe as torequire that the tackle be constructed to withstand hard service and beof a heavy construction. In such cases, it is apparent positioning ofthe tackle relative to the load after the full weight thereof rests uponthe top of the load could only be accom plished with great difiiculty,if attempted manually by workmen standing on the ground.

' It is seldom necessary to change the position of the counter-weight 43with reference to the apertures 46 once a generally applicable conditionis established. The exceptionsare in case the size or weight of thechains 87, 38 and 41,01 the hooks 39, be varied, or seeondly, if theposition of the connecting member 21 with respect to its positionrelative to the center of the arms 19, is altered, as in view ofcircumstances to be described hereafter.

In order to insure that the tackle 18 is securely fastened to the frameso as to prevent dislodgement therefrom during handling, the specialtype of hookmember 89, is provided.

The body portion 50 of the hook is grasped by the operator and firstinclined from the vertical sufiiciently to permit the lower portionsthereof to be inserted under the longitudinal beams 12 until the beam 12contacts with the back of the recess 5%. The hook is then lifted,causing the beam 12 to be accommodated in the depth of the recess 54.The operator then thrusts the upper part of the hook forward until theextension 51 passes beyond the top of the beam 12 and until the beamcontacts with the main body portion 50 along their entire adjacentsurfaces. This brings the upper lip 53 beyond the beam after which theoperator permits the hook 39 to drop of its own weight, thus engagingthe beam between the upper and lower lips 53-53 and the body portion 50of the hook. The effect of such a construction is to permit the singleground operator to position the four hooks 39 successively, which he isable to do because once a hook is positioned the lips 53-53 insure itsmaintenance in position around the beam and the operator is thus free toproceed to the next hook without requiring the attention of otheroperators to insure that all the four hooks are securely in positionbefore the load is lifted.

Due to the fact that the tackle 19 is suspended from a single point, atendency of the load to tilt if it is inaccurately balanced withreference to the connecting member 21 becomes apparent as soon as thetrailer is lifted from the ground. To overcome this, it is desirable toposition the connecting member as near as possible to the center ofgravity of the load. This may be accomplished by securing the dependingportion 27 to the arms 19 at that aperture therein which will give thedesired balanced condition. Once a balanced condition is establishedwith reference to a typical load it will thereafter be unnecessary tochange the location of the depending member 27 with reference to thearms 19 provided reasonable care is exercised in loading the lumber soas to insure that the connecting member 21 will always be as near aspossible to the center of gravity of the load. In practice, it is seldompossible to locate the depending member 27 with suflicient accuracy toprevent the load 19 from tilting slightly when suspended above theground. Any tendency of the load to shift, due to said tilting, ishowever, obviated by increasing the friction between the sections oflumber comprising the load.

In order to positively thus prevent shifting of the load, specialfeatures of the tackle are provided. As soon as the hooks 3939 arefirmly secured over the beams 12 at the brackets 16-16, the operator ofthe crane begins to raise the crane hook v26, with the result that theparallel arms 19 are raised until the chains 37 and 38 become taut. Thecontinued elevation of the crane hook 26 coninues to raise theconnecting member 21 with the result that the balanced condition of thearms is overcome and they pivot about the pin 29 and the dependingmember 27 Since the Ushaped band 33 is rigidly secured to that side ofthe arms 19 which bears the interconnecting flexible member l1, andsince the chains 37 and 38 which are connected to the U-shaped bandthrough the aperture 35 are now taut, the continued hoisting of thecrane hook 26 causes the flexible member 42 to bear downwardly until itis bound tightly across the top and from side to side of the lumber pile17. In the arrangement shown in the drawing, wherein it will be notedthat the distance between the pin 29 and the U- shaped band 33 isapproximately one-third of the distance between the band 33 and theflexible member 41, distributed a downward pressure of approximately2,000 pounds is applied to the lumber load by the flexible member 41, ifthe weight of the load including the trailer is approximately 6,000pounds, as may frequently be the case. Since a downward pressure ofconsiderably less than 2,000 pounds is ample to prevent shifting of thelumber when the trailer is tilted at any angle conceivable under serviceconditions, a satisfactory margin of safety is provided such as willinsure that a device of the character de scribed may be successfullyoperated by a one man ground crew, it being necessary for him to adjustthe books 39, 39 in the manner described above.

In Fig. 2 of the drawing, a dotted line representation is included whichshows the extreme inclination assumed by the arms 19 where approximatelyone-half of the usual load of lumber is carried. It will thereby beunderstood that the tackle is capable of chicient use regardless of thesize of the pile of lumber 17, since the arms 19 are free to rotatethrough a sufficiently large angle as to permit the flexible member 42-to apply pressure upon the top of a load of lumber of any convenientsize which may be contained by the platform 11 of the trailer and theconnecting member 21. The operator of the hoisting engine, by lifting onthe crane hook 26 and forcing the flexible member 41 downwardly againstthe pile is then free to hoist the loaded platform to any locationwithin reach and through any maneuvers of which the crane is cap ablewithout dislodging or causing any shifting between portions of the load.The pressure exerted upon the lumber pile by the flexible member 41 maybe varied by changing the position of the connecting member 21. Forinstance, the pressure may be increased by decreasing the distancebetween the U-shaped band 33 and the connecting member 21 or it may bedecreased by increasing the distance between the band 33 and theconnecting member 21. This may be readily accomplished by removing thepin 29 and moving the depending; memben 2'! into position oven-any enemaapertures. provided .fori-that; purpose: irmztbm arms 19 ,andinsertingvthe; pin; 2am; it in such =p ositi,on:-..

Although the. inventionghasa been} disclosed and described as applied toan apparatuslfori handling .lumben'itiisaclear; thlatiit isisusoeptibleof numerousinodificationsstoeadapti it to handle material :of.a-nature anrliniformsi other than; thatdisclosed, and itissintenided'therefore, that the;inventiombevlimited only by the spirit; and; scope 1of the appended claims.

What-isclaimed is;::

1. In a material handling. apparatus-,; a; platform forsupporting thematerial, a. flexiblemember, and a Lpivoted iarm-u for" carrying, theplatform includin-g memission-retention ally; engaging: the ,flexi'blemember with; that top .ofzthe materiala In a material handlingapparatumi. a; tackle comprising a ipivoted-arimandi a. flexible. membersuspended therefrom; for:eIig-ag ing the material, to prevent shiftingthereof when thesmaterial is lifted;

3.;Ine a; tackle, a pivoted r arm as flexible; member suspended1therefrouiaforiengaging a loael, and means spacedfrom thepiwot point:of z' the arm-.1 01. 3 tilting thevarmuto. 03 121565 the flexible memberto retentionally engage;the;

load.

i. In a a material handling; apparatus,y, a;- tacklea'ncludingia paired} pivoted arms,-;a flex;- ible. ineinberconnected tliereto.forfretentionea ally engaging the materialandasecond'flexisi ble member:suspended therefrom. for: carry ing the. material and tori-tilting;thei.:arm to:;. cause thezfirst fiexiblemember to engagerthe load.

5. In. a material handling apparatus,;asns.-. pension -m,eans,. an; arnrpivotedri'theretoy means associated with. 1 one end. thereofrifon:normally; zmaintaining the. army; horizontal; means; secured to thearmontheoppositeaside: of the pivotal point. 1 thereof. from. the susapension; .means, for supporting; the, material and means associated withthe other en'dnof'" the-arm toxengage the supported material when .theharmuis inclinedi 6..- In a material handling apparatus, a sues: pensionmeans, a. pair of parallel. arms pive oted thereto at; an;intermediatepoint, mas. terial supporting means piwoted :to the arms.atan; intermediate point, and. .flexibleimeansi interconnecting-the endsof thearmsonearer: the pivot, pf ;the: material supporting: means towrap around a portion ofithenmateriali hsnsuspencleda;

7. In a.: tackle, a pivotedfarm aafiexiblei member suspended therefromfor retentixim. ally ;engagingg;a load; and asecond member suspendedfrom the arm. for tilting the arm to cause the first member to engagethe load.

8. In a material handling apparatus, a tackle including a pair ofpivoted arms, a

flexible member connected to both arms for retentionally engaging thematerial and a second member suspended from the pair of arms carryingthe materlal and for biting the arm to cause the first member to engagethe load.

9. In a material handling apparatus, a suspension means, a pair ofparallel arms pivoted thereto at an intermediate point, materialsupporting means pivoted to the arms at an intermediate point, andflexible means interconnecting the ends of the arms nearer the pivot ofthe material supporting means to closely engage a portion of thematerial when suspended.

10. In a material handling apparatus, a platform for supporting thematerial, a flexible member, and a pivoted arm for carrying the platformincluding means for retentionally engaging the flexible member with thematerial.

11. In a material handling apparatus, a level platform for supportingthe material, a tiltable arm for carrying the platform, a flexiblemember at one side of the axis of the arm, means for engaging theflexible member with the material when the platform is being carried anda counterweight at the opposite side of the axis of the arm forbalancing the arm.

12. In a material handling apparatus, a tackle including a pair ofpivoted arms, a flexible member connected thereto for en gaging thematerial and a member suspended therefrom for carrying the material andfor tilting the arm to cause the flexible memher to engage loads ofvarying heights.

18. In a material handling apparatus, a tackle including a pair ofpivoted arms, a flexible member connected thereto for engaging thematerial and a member for engaging the material and amember suspendedtherefrom for carrying the material and for tilting the arm to cause theflexible member to engage the load and to conform closely to thesurfaces of loads having'irregular contours.

14. In a material handling apparatus, a load supporting member, a memberengageable with the load supporting member comprising a recessed hookhaving portions partially enclosing the recess, the aperture be tweensaid portions being narrower than the load supporting member, whereby apartial rotation of the hook is required to engage it with and disengageit from the load supporting member.

In Witness whereof, I hereunto subscribe my name this 27th day ofDecember, A. D.

WILLIAM SCHROEDER.

